The effects of four front-of-pack labelling schemes compared to standard Nutrition Information Panel, on the healthiness of food Purchases among adult Australian consumers.

The study intervention include four different front of pack nutrition labelling schemes that will be shown to study participants via a smartphone application. The study intervention duration is four-week. The labelling schemes that will be tested in the study are: *Colour-coded multiple traffic-light labels (the current public health gold standard). Traffic-light label uses green, amber and red colours to indicate the relative levels (low, medium and high) of four nutrients (fat, saturated fat, sugar and sodium). *Monochrome daily intake guide labels (the current food industry option). This label provides information on the level of energy, fat, saturated fat, sugar and sodium per serve and the percentage of each on the average Australian daily intake. *The ‘energy stars’ based front-of-pack nutrition label format selected by the Federal Government. The label assigns a rating from 0.5 (less healthy) to 5 (most healthy) stars to foods basing on their Health Star Rating score, calculated from energy, fat, sugar and salt content, and adjusted for other components, such as fruit and vegetables. *Advisory labels that warn against the purchase of less healthy products and encourage the purchase of more healthy products. In addition to information available on the standard nutrition information panel, this standard label will provide a green sign indicatig a food being a healthy choice or a red sign indicating the food being unhealthy and suggesting consumer to avoid. The warning signs are calculated basd on the food nutrition profile score in each category. participants will be able to use the smartphone app to view nutrition labels as often as they wish. To view a nutrition label, users scan barcodes of packaged food products using the smartphone camera, and assigned labels instantly appear on the phone screen. Automated reminder messages via the smartphone app will appear three times per week on their smartphone screen to prompt the participants to use the app.